G`day to all.I have just finished machining the material kit of this engine and have had no success on running same.All machine work was done to specs.The problem seems to be the initial position and timing of the displacer and the power piston,as there seems to be a lot of conflicting opinions out there.As this was not a pre machined kit,I believe that this particular engine is a bit hard to get running.The displacer has suggested clearance and the power piston passed the "spring test" in the bore.There is negative friction in any parts and freewheeling is good.At 78 years young ,I am getting a bit frustrated with the end result, as this is my first attempt at making one of these engines.

Hi Bob, just not sure which motor that is, but the important thing about the timing of these motors is that the displacer crank is 90* ahead of the power crank.another test you can do on the power piston is, take the cylinder off the motor and hold it vertically, fit the piston in the cylinder, and it should drop though, but if you block the end that should almost stop the piston sliding through.I started building these things about 1990, and at first they seemed to take a bit of getting going, and they do have a reputation of difficulty, but if you get the friction down, reduce leaks to a minimum, and as I'v said, get the timing near enough to right. Sometimes a few degrees + or - can have benefit.Have patience, it will go.Best wishes Ian S C